Anticoagulant factor-deficient women have an increased risk for venous thromboembolism during pregnancy and the postpartum period. Although data from an appropriate randomized clinical trial are lacking, the frequency of venous thromboembolism seen in deficient women might justify the use of anticoagulative prophylaxis during the third trimester of pregnancy and the postpartum period.
SummaryHereditary deficiencies of the naturally occurring anticoagulants are well recognized conditions predisposing to recurrent venous thromboembolism. Since thrombotic phenomena have been implied as a cause of abortion and stillbirth, we hypothesized that these deficiencies increase the risk of fetal demise.A group of 129 female subjects who had been pregnant at least once and who had a family member with documented venous thrombosis associated with a deficiency of AT, PC or PS were studied. We first assessed the obstetric history and subsequently determined the deficiency status. In the 60 deficient subjects 42 (22.3%) of the 188 pregnancies resulted in miscarriage or stillbirth as compared to 23 (11.4%) of the 202 pregnancies in the 69 non-deficient subjects. The relative risk of abortion and stillbirth per pregnancy for deficient women as compared to non-deficient women was 2.0 (95% C.I. 1.2-3.3).
The prevalence of deep vein thrombosis in female patients with antithrombin III (AT III), protein C, or protein S deficiency who are on oral contraception has been compared with that of patients with activated protein C (APC) resistance. In the latter case the prevalence was lower (36.4%) than in the AT III deficiency group (71.4%) but similar to that seen in the protein C and protein S group (25%).' Furthermore, venous thrombosis occurred with APC resistance much later than with AT III, protein C, or protein S defects. The time lag between onset of oral contraception and thrombosis (~16 cycles) was not statistically different from that seen in a group of women who were known to have no antithrombin III, protein C, or protein S defects. It appears that as far as the interaction with oral contraception is concerned APC resistance is a much less severe condition compared with other clotting inhibitor defects. Key Words: Oral contraceptive—Activated protein C resistance—Deep vein thrombosis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.